Is the whole space one functional area? Because usually people use a couple of rugs to define different areas -- one for a furniture grouping that's for seating, another for a play zone, another for... Anyway, way cheaper than a monster rug -- if you wanted rug everywhere, then maybe carpet was the way to stay.

Usually the largest standard sized area rug is 10' x 14'. So for a rooom that size, you'd have to do one of two things: (a) create two conversation areas, each with a smaller rug or (b) have your carpet supplier cut and bind a broadloom carpet to the correct size for the space as you've already investigated. FYI, $3500 for a custom rug that size is not expensive. A 10' x 14' from Pottery Barn will cost you $1,600 or more. So if you did two, you're spending about the same amount as your custom rug.

I've had excellent luck with large indoor/outdoor rugs in the family room. It sounds like it would be rough but it's soft and very comfortable to walk on barefoot. I think they're a great value for the money and so easy to spot clean spills. It's great for indoor use. There's many choices on-line. ( I have 4 young grandkids, 2 dogs and a cat...works for me).

Thanks acm - the area is used as one large space. We have a very large sectional that's 12 feet long and of course my husband bought the largest tv he could find! LOL After living with wall to wall carpet for 12 years, it was so gross. It also did a number on my husband's allergies. He feels so much better that we got rid of the carpet in that room and in our master.

petlovermarcie - an indoor/outdoor would be great for that space. How large are the rugs you bought?

The ones I have now are about 10' x 12' and purchased on https://www.rugs-direct.com I didn't need a custom size but I think those are available. There's lots of sites that sell them in solids, stripes, patterns etc.

$3500 for an area rug? Is the yarn spun of gold? What size are you planning to have? Wall to wall carpet can be cut down into area rugs. A $50 yd carpet (roughly $5.50 sf) that is ordered as 12x12 should only cost you around $800 plus binding and tax.

I was looking at 18‘ x 20‘ so that there was a 4 foot border of hardwood showing

I simply used two identical rugs and hugged them together with carpet tape. Worked like a charm to go the length I needed.

Donna - do you see the seam at all? I never heard of carpet tape, i'll have to google it :) Do you have any pics of your rug? Thanks!

Thanks so much for sending, Donna. I'll check it out on Amazon.

An 18x20 is 40 yds. Most carpets come 12' widths. The best route for this would be to order a 12x36, cut in half, seam the 2 together side by side and trim the additional 4' off one side. This will bump you up to 48 yds. A $50 yd carpet is considered high end, carpet only. ((Here in Texas, my high end carpets sell for $40-$50 yd, carpet only)) So, if we're still budgeting with that number, you're up to $2400. You're also looking at 76 linear feet (LF for short) of binding which can add up really fast...lets say they charge $10 lf. (Which is high but not knowing your location..who knows what they charge) This would put you at $3160 plus tax. --I understand why it's so high, due to the size of the rug.
If you wanted to get around not having to bind the carpet and save a little money.. Shaw carpets have a patented soft backing. This backing will not scratch your wood floor. If you pick a product that has a high pile height, like a frieze (shag), you don't have to bind the product. The pile will lay over the edge and you'll never know it wasn't bound. Carpets with this soft backing are cross threaded, the yarns will not pull out. A vacuum will not cause the yarns to pull loose.
As far as carpet tape...any sticky tape will work. Duct tape...masking tape. Anything 2" or wider.

We don't see the seam but my two area rugs are short shag. If it was a lower nap then I would have cut both edges off before taping. I've done that too. Good luck and get what makes you happy.

FLOR tiles are nice, especially with kids because you can clean or replace individual tiles and you can go as large as you need. Not sure of the cost for that size. My dad loves them. He bought two different colors and rearranges them into different designs occasionally.

If my room is 22'x24', and we have a 12' long sectional couch, what size rug would work best? I was planning on getting an 18'x20'...my husband says that's too big and we could get away with something much smaller. What's the rule of thumb? Thanks!

I think the ideas of sectional rugs works well in situations like these.

Why does it have to cover the entire room? Why not the seating area only?

If I do the seating area only, what size should I look for? My sectional is 12 feet long.

I assume it is 12' along the back. How long is it from the edge of the sofa to the cushions of the side piece? Like this diagram.