I can't really empathize with your statement...
Who forces you to buy those 6.75$ balls? Not like you got clubs with fast meters anyway, nor do you need them to score low with those clubs from the short tee's.
You got the best clubs available at that level (except your Irons but thats a different story),
Why do you"have to" pay 6.75$ for those outragous max meter balls? Their whole purpose it the extremely slow meter, which doesn't seem to help you with 65% Driving and 68% GIR, while they lack spin and have less durability.
You can get Callaway tour (i) s balls for 2.50$, with 1 dot less in distance but 1 dot more in spin (huge plus), additionally, they even have more durability than those rip-off max meter balls...
Either way, that's that, what exactly do you mean by 'incentive'? You're not playing tournaments of any kind.
Or do you mean the incentive to move up to the next tier? Well, there are other ways to lower your average: By beating higher tiered players (in your case tour masters and above) in Scored or Challenge Matchplay.
But...if you can't get your avg. low enough to advance to the next tier, you shouldn't be in that tier, while others who should be one or two tiers higher don't play any kind of stroke format on purpose to stay on the Lady tee's.