I dont run a pro shop but I have seen many in my area come and go.
Most of the pro shops that Ive seen start out as a part time operation and eventually work their way to a full time buisness. I know of at least 7 proshops that have opened in the past five years and all of them are closed now. This is in and around a city of close to 225,000 people. There is only one that has been in buisness for several years and is doing pretty good. I think the key to their success is diversification (They carry everything from archery , guns, fishing suppleies, and wildlife art etc.) and great customer service.
Are you just planning on selling and servicing archery equipment? Or are you opening up an all around sporting goods? Diversification makes a big difference\
in long term success.