The amount of time a clearo coil will last really depends on the juice you vape, and certain flavors will gunk up the coil quicker than others. To get a clearo to last 10 days maintenance free without degraded performance would probably require using flavorless juice, but I don't have experience in that area to say for sure. I do know that even with my light fruit flavors, I can only get 3 to 4 days of sustained use from a coil before it needs to be cleaned.
As for cheap, I don't think you'll be able to do better than the ViVi Nova (or mini), Vision 2.0, or Kanger T2/T3 clearos right now. The replaceable heads run about $2 to $2.50 and being able to remove them does make it easy to do some light maintenance. Even if you don't want to dry burn, then just rinse them in warm water between fill-ups and that should give you some extended life. With the low price of the heads, you could probably treat them as disposable and still come out ahead over the non-replaceable Stardust (CE4+) series.
I hope this helps.