I'd put the ones you have in the 'fridge to slow their growth. It's not an issue that they are already sprouting, it's actually a good thing and will speed their growth in the garden, but it *IS* a problem if you can't plant them for a while. So get them in the 'fridge ASAP.

As for buying more......up to you, but the best deals are found at local stores if they carry potatoes. My local Southern States sells them for something like $0.43 per pound!!! Of course that does you no good if you can't get them locally.

The ones I don't get locally, I get from an outfit called DeBruyn Seeds (see the link below). They have fantastic prices on potatoes and asparagus. For instance, you spent $15.50 for 2 lbs of Yukon Gold at Territorial, but DeBruyn has 5 lbs for $3.49 and 50 lbs for $19.50!!! For a mere 4 extra dollars, you'd get 48 more pounds of potatoes!!!!!

I've been buying both asparagus and potatoes from them for years and have never been disappointed. I have no affiliation with them, just a satisfied customer

Here is a link that might be useful: DeBruyn Seed Co