I just scoured Facebook Marketplace.
I got my 1080ti for $40 because it had a broken fan. The seller said he can't guarantee it worked because he smelled burning, shut the computer off, and didn't try it again.
I got the exact replacement fan for $8 on Amazon. 2 years later, it's still rockin strong!
eBay is your friend here. Looks like there are a good number of turn key Nvidia GTX 1070 cards available right at your budget from some highly rated sellers, using this search string in the computer components and parts -> graphics/video cards category yielded 160 results:
1070 -broken -read -only -repair -empty -box
Here's a link to the actual search :
be sure to make generous use of '-' terms as seen in my search string to filter out the giant wad of irrelevant/useless results that'll come up, and read the recent/seller feedback for the sellers you are considering doing business with and stay away from single digit feedback sellers with pricing that is far cheaper than expected for the item - (e.g. a $150 brand-new RTX 3080 from a seller with a feedback score of 5 is very unlikely to be legit 🫥) and you should find what you are looking for. Good luck!
Second hand will do you better than 90% of anything new you can get for under $100USD, most are trash tier that are little improvement over integrated graphics. There may be compelling new models in the $150-200 range.
The Nvidia 10xx series are a solid choice for the performance over prior generations (go with 1060 or better). Failing that, a 970 or 780 or better will be in your price range.
AMD R# 200, R# 300, RX 400, RX 500, RX 5000 series are pretty good depending on what you can find. I think that will fit the budget range you are looking for with a solid performance uplift.
Second hand P620 or similar should be good. A new sub 100 card is hard to find, let alone of it should be any good.
From what I’m reading Fusion360 is not as dependent on GPU as it is CPU.
Someone had suggested a 1660 Ti as a good midrange solution for running Fusion360.
Keep an eye out for used 1660Ti’s hitting the market as there is another release of new GPU’s from Nvidia coming up soon.
Might just be the right time to snap one up for ~$100.