E. and I both belong to Large Format Photography Forum. A lot of people on there suggest starting out with 4x5 so your initial investment is lower. Buy used and you can always sell for close to what you paid if you decide it's not for you. Of course you can always sell your 8x10 gear in the same manner.
I started out with 4x5 but I could just as easily started out with 8x10. If your heart is set on 8x10 then go for it.