...if it is anything like bikes, the correct number to have is n+1 where n is the current number you have.
It is exactly like bikes. I have 5 bikes and 13 finished guitars, with a bike build in parts, and several guitars in states varying from rough shaped body blank, to awaiting final finish coats.
GAS (Guitar Acquisition Syndrome) is very real and quite incurable.
FrankenLab Hand crafting guitars, because Death Rays are expensive.