Ok, $30 to remove the old and replace with my own tire. but an extra $25 to balance it?? we are still looking for our first rv service shop... motorhome beginner...

Sucker... Just kidding, @ $ 120hr(rotflmao) shop rates for your 30 min job? = $ 55 , you got a deal.
Welcome to the world of RVing

Welcome to the forums!

If that were done at a tire shop, that's a bit pricey - I don't know where in FL you are, but I had all four rears balanced, alignment checked, and front bearings repacked in Gainesville for $245.

I use anti-freeze to balance my tires. Use a bicycle to inject into the tires. 50% solution and about a pint per tire. Cheap active balancer. This is not a new technique as truckers have been using it for years.

We just replaced four tires while traveling through Arkansas and the dealer placed small bags of silica beads , one in each tire as they were assembled. These are dynamic balancers and leave no residue or liquid. Here is their site: http://www.bobbyhenardtire.com/
You can call them and get some and install them easily by just deflating the tire, breaking the bead and sliding one pack into each wheel. He charged $3.00 each and we have no more balance issues. On 22-1/2 inch wheels the bead relaxes as soon as you deflate the tire so it is really easy. Of course inside duals are more of a problem.
Worked for us.

thanks folks, I had a feeling "welcome to the world of big Rigs" I like my class A, nice kinda cozy, and trailers seem flimsy to me.....jl

Someone needs to explain to me the theory & the physics of installing fluid, or bags of silica gel in tires in order to balance them, & how one calculates the appropriate amount of material to introduce. I also would like to know why, if this is system is so simple, foolproof, & effective, almost all tires are still balanced the old-fashioned way with external weights.

I found this:
http://www.patentstorm.us/patents/5766501/description.html