Eventually there comes the time when things have to go and I think your fixtures reached that point. If the plumber can't fix that the right way, and I have seen some plumbers like to "rig things" just to make things work when people don't want to spend the money and down the road, you will be faced with new problems and it will cost you even more and it usualy happens at the wrong time.

Before the baby comes, replace all the fixtures and get it done the right way, not to mention the tiles also have seen better days, now it's the time to do it especially with the baby on it's way, this way you get all the mess out of the way now and you and the baby can enjoy the new bath.

Not sure what the tub looks like and the rest of it, i.e vanity, etc but if most of the major items in decent shape, it shouldn't be too much to make a facelift on everything else.

Good luck and congrats.

I was living in a condo constructed circa 1965 and the valve turning water on and off had frozen in the tub/shower. I managed to get someone to turn the water off since it froze while water was running and then a plumber came in and replaced whatever needed to be done so that I had a working tub/shower again.

Luckily I had a shower in the guest bath because just turning off the water in my building costs $2000 so I waited until I could split the cost with other plumbing repairs requiring a water shut-off. There are angle stops for sinks and toilets but none were installed for the baths or showers.

They had to access whatever needed to be done through the back so it wasn't a simple change - i.e. it wasn't just replacing the trim. The shower wall backed up to the back wall of my closet so luckily I didn't also have a cosmetic fix in my room. Obviously if they had to come in through the front it would have been much more difficult since the actual tub/shower would have had to be fixed (hideous acrylic type of one piece from the original construction)

They also installed a mechanism so that the water could be turned off in the event that I needed future repairs - this was a big deal as well because I lived in a building where the water to 122 apartments needed to be shut off (all water in building) if plumbing repairs were made where there were no angle stops or other ways to turn off water to the fixture.

It wasn't a cheap repair but it wasn't hugely expensive since plumbers charge by the hour and it didn't take them a huge amount of time to do the fix. They also supplied trim that worked with whatever new "rough" they had installed. It wasn't gorgeous but it worked and it all got demoed a few years later. I am sure it was a few hundred dollars which was a significant cost but not as high as you might be imagining it be.