Yes, 50$ would be a good price but it also depends very much on market.
Right now, Avalanche is at 60$ and maybe it can get even a higher price when more updates will be published, like subnets for Avalanche or an update for lower fees.
While Bitcoin is very high currently, if Bitcoin drops Avalanche will most likely drop, too.
Well, AVAX got past $50 per coin before the year came to an end. It's trading at more than $67 per coin at the time of this writing.
Right now it is already almost 100$ and while Ethereum has still very high fees, new projects start looking at more innovative coins like Avalanche.
Especially for small investments, Ethereum fees are making transfers extremely expensive.
So AVAX can increase more than $100 by the end of 2021 but that will happen if bitcoin still increase. My prediction for AVAX can be at $150-$200 but people still hope to ETH than AVAX because ETH will be more popular than AVAX. This month could be a good month for AVAX to increase more than $100 for the next target so, in the next month, the price can be at $150. Maybe AVAX still needs to promote their project so people can know that AVAX is also a good project that they can use for their investment.