I looked at the internal hubs and they are expensive. Since this is going to be a low cost build do you think maybe if I set the chain on the wheel to the big sprocket and since the chain on the front sprocket is on the small one I would have a ok gear ratio ?
Here's the biggest problem with cheaping out; it often means compromises on safety, functionality, and dependability. Almost every time cheaping out ends up being more expensive than simply doing it right the first time.
A broken chain can cause damage to both you and the bike. With no pedals, it also means you'll be pushing the bike home or carrying it if the spokes get destroyed.
If the chainsaw turns 3600 rpm and you run a 10t sprocket to a 44t chainring; then run the 24t chainring to a 28t rear cog that's around a 5.13\1 reduction which won't be a low enough reduction.
My max hp is at 7000 rpm and my reduction range is 66.79\1 to 16.25\1.