I often wondered about a pay monthly scheme. A cricket bat is the same as any expensive item and credit should be offered. It may be a natural product but so are many pieces of furniture and you wouldn't think twice about taking credit out. Don't knock it and give them the benefit for a good idea.
Regarding saturation I think the market has a way to go. With the advent of T20 cricket, more people want specialised bats and are becoming aware of different brands. I think the nature of buyers will change from the 1 bat in 20 years older buyer, to the younger, bat a season buyer. Cricket bats will become more disposable and buyers may possess more than 1 bat a season. Some brands will create demand by marketing and awareness, others will have a geographic area they can survive in. Like all business, those who don't adapt will go to the wall.
If you want proof that any of this, then look at this forum and tell me people aren't buying more bats.