Ok, Ill confess... Easy Tech here... but ive also done a VERY VERY VERY small tech business for myself, and worked as a tech for a school district...
As for pricing:
Diagnostic is 69.99 this is mainly for hardware issues or really weird windows problems BSODS, no boots, corrupt boots, looping, etc. Then charges vary depending on solution... restore 100, maybe parts + install, major work gets outsourced @ a flat rate.
Virus Removal is 129.99 INCLUDES DIAGNOSTIC (NOT + 69.99 from above, this used to be seperate 69 + like 89, so its actually cheaper than it used to be), and usually anything extra required to get the PC back to normal (least my store does), except maybe installing NEW A/V, thats a Software Install - 29.99 plus software (maybe 24.99, if its one of our specially priced tech nortons, or something silly)
Data Transfer / Recovery: Simple transfer is 100 per 10GB (but most techs dont double charge for more, unless its takes exceptionally long, involving multiple attempts etc. Then there is a charge for recovery which is 250... yes if it has to be sent out, we send it to Seagate, and prices do range from 1000-2000 (no data - no charge).
Believe me, we dont want to keep your pc for long periods of time, but we are relatively new to tech, so we still havent balanced out man power vs work load... and occasionally get backed up, and some stores do not have the proper workspaces, but this is slowly changing (but we have a lot of stores, i can drive by about 6 in 15-30mins.
edit: crgky covered some of that better than me while i was writing my essay
edit2: An interesting charge that im not a fan of is similar to your 1st comment... if they have viruses, and we decide a system restore with data backup, we may need to do virus removal on your recovered data... i usually drop that last charge though, but i believe technically it would be diag 69 + backup 100 + rem 129 + sys restore 99, but usually if its in cuz they just think its viruses, then it came in as a FREE PC TuneUp (ill save comments on this for another thread) so no Diag, and usually i wont charge virus removal on the data backup if our tech pc simply catches them and no extra ordinary removal techniques are needed.
edit3: similar to link above, this is the brochure we have instore..
http://www.staples.com/sbd/cre/marketing/tech_09/pdfs/staples_tech_services_brochure.pdf
There is a rate on the books for an hourly rate $69.99/hr, my store rarely uses this, usually opting to build the total price out of the specific services, imo it is more clear as we can say this is the price per each item for what we did, its harder to argue that we did something than it is to argue how long it took us to do it. Onsite is also done on a per service basis, but they also have a per hour charge, but atleast this makes sense as the customer sees how long it takes, but again dont think its used often.