I’m afraid I’m going to burn through pricey bags on the mini.
You're not keeping your eye on the ball here. This sentiment is sorta like buying a more expensive car because it gets a bit better gas mileage or uses regular gas instead of premium. At some point the gas savings will pay for themselves, but how long will it take and at what cost of not being able to use that money for something else now ? ? ?
Buying into Festool has a high hurdle. Worrying about what consumables costs is counter productive and a waste of energy.
The one constant throughout the lineup is the cost per liter of bag capacity goes down the larger the vac. So if your overriding focus is lowest cost per liter of dust made, then the CT48 is the clear winner. With the most capacity and lowest bag cost; your labor savings not emptying the bags as often with cheaper cost is enticing if you are generating a lot of dust. Like maybe a floor sanding operation. A hobbyist sanding a few projects and cutting a few sheet of ply every weekend is unlikely to fill up a bag in a year. And a box of bags might last a decade. At that rate, it's going to take a long time to recoup the xtra $250 the CT48 costs over the MINI. It's going to take on the order of 17+ bags on the MINI before you start to see a payback for the upfront costs. Doesn't sound like a lot, 3 boxes, but really think about how often you change a bag. We use MINIS for installing kitchens. About 1-2 a month, and it gets used for sizing end and backpanels with a TS55. A hand planer is hooked up to it too. Sometimes a Domino or Biscuit joiner, and for general cleanup of drill swarf and other debris. Occasionally a router is used to make a dado for a light strip. We use roughly a box of bags per vac, per year.
A MINI or MIDI makes sense if you need the vac to reside under a small workstations or you're going form jobsite to jobsite everyday. Carrying a laden CT26 up is cumbersome and heavy. A CT48 would border on a two man job for some oldtimers. Some guys like to buy a separator to save on bag cost. Either Oneida's or now Festool's offering will keep your bags from filling , but again ...... at what cost ? $300-$400 buys a
LOT of bags. If you're planing lots of linear feet this might make financial sense. Otherwise it's penny wise and pound foolish.
For a fixed base shop with generous room, the CT26 or 36 probably makes the most sense.