Sony RMT-DSLR2 Wireless Remote Battery?
Rush rush, ten days and new gear desired quickly and cheaply, ...
does make little sense to me. Sorry and do
previsualize your shots as you go around. They will come out better, even without that last piece of gear, I hope.
Incidentally, these type batteries are available in the battery sections of most US food stores for hearing aids etc use. One will last you a couple of years.