I know if it was me - i wouldn't do it. Most of my maternity stuff was hand-me-downs except for a couple nice new tops i got from my mum for my birthday- would've been under $20 and i wore all the time. But i did buy a maternity dress for $40- my most expensive item i ever bought- i got heaps of wear out of over summer and a little bit more wear out of it just after DS2 was born- as it was nice a flowy. I could get away with wearing now- as it not really maternity looking (but last summer it seemed a popular maternity dress- so i didn't wear it- but might get it out this summer if i don't see many pregnant women wearing it). But then again i don't like spending much money on normal clothes - i probably still wouldn't buy it at $90 even if i was a normal top...lol- but i am a bit of a scrooge with money.

But if you love it- get it. Maybe you can try to then sell it on ebay for close to purchase price if its still in excellent condition???