It's already too late. But, you're in luck as I'll give you $100 for it. 😀
Do you use your iPad? Will you continue to use it over the next 4-6 months? Would you "miss" it if you didn't have it? If so, then you shouldn't sell it just because it's worth more now.
If you don't ever use it and just want your money back out if it, then it will probably never be worth more than it is today.
And if you're looking to get the best bang for your buck, you should buy used or one generation behind anyway.