@Vindicare @MAB Thank you for your responses!!!
So, armed with your advice, I spent all weekend trying to figure out how to get the VIP I needed to get up to 2600. Needless to say, that whenever I decided on anything, it either was sold out or was sold out by the time I was all set to buy it. So today I just bit the bullet on a Hidden Side set that closed the gap on VIP points. Naturally, I spent more on that set then the $20 I will save with the vouchers I can get.
Now, I just refresh and wait for the big set I really want to get this month and hope it comes in stock. I'm trying to follow @MAB advice not to get the vouchers until the last minute but I'm concerned that set will disappear again. I already missed it once after a notification mail sent while I slept. Still I haven't gotten the vouchers yet and remain hopeful.
After all, if they see customer request for sets with notification emails, surely they will restock those sets at some point soon. I hope I hope. Thanks again for your advice!