I am in the same boat. There is a huge price variance between materials and brands. MTI has a few acrylic ones that are affordable, Kohler acrylic is mid range, but my preferred brand is Victoria and Albert in solid surface. Still deciding if I want to spend the money on the solid surface :)

The one you see the day after the tub you ordered is delivered.

In my previous house I used the "Rolls Royce" of freestanding tubs and then realized it was a waste, as it was barely seen by anyone and we aren't bath people so it only got used a few times. It was really pretty though and felt solid!

https://tandlinternational.com/

When we built our current house I went with one that looked nice, could take a deck mounted faucet and was a much better price than the one I had bought before. Sure, it isn't as solid feeling as the old one, but it looks and functions just fine, specially since we still aren't tub people and it will rarely get used.

https://maax.com/product/ariosa-6636-acrylic-freestanding-bathtub/106267/106267-000-001

The "Rolls Royce" tub was 5 times the price of the new tub, but that doesn't include inflation, so probably even higher if you purchased today.

Coincidentally, I picked out the freestanding tub today as the plumbers were at work.

We had a Maax bubble-air drop-in on a previous build and it has held up well 4 owners in.

Previous worthy bath.

The freestanding tubs strike me as accidents waiting to happen. Jumping a three-foot barrier on wet stone! But this is for the re-sale market the moment we move in and it's what's in demand. Bubble airs, let alone those horrid whirlpools, which always remind me of the one in the corner of the football coach's office in high school, are out.

@nikkync if you use your tub, I think the Victoria & Albert is worth it. The volcanic limestone supposedly holds heat better, though it's hard to know for sure. Their tubs are solid and quite heavy, and certainly a lot higher quality feel than acrylic. If you don't use your tub, then it didn't matter nearly as much.

I have 2 victoria & alberts and I love them (dual primary suites). I enjoy taking baths and use mine frequently. I will say the only downside is that the edges are narrow and rectangular, not smooth, wide and rounded as on acrylic tubs or cast iron. That makes it slightly less comfortable getting in and out of the tub, but I really wanted the solid surface for the looks and heat retention.