It depends on a few things - I'll use the about the prices from my clinic for an example (but expect the exotics fee and antibiotics to be more expensive)
Scenario 1: able to lance and clean without surgery
Exam Visit $50
Wound Care $30-$50 depending on size
Oral antibiotics $27 - $60 or injectable antibiotics $75
OSHA Disposal Fee $3
Scenario 2: Abscess needs debridement, surgery, a drain to be place, then removed (not as common in mammals)
Exam Visit $50
General Anesthesia and Surgery $250-$600 depending again on size and complication
Oral antibiotics $27 - $60 or injectable antibiotics $75
Topical wound care medication $0-$30
Recheck Visit $45 (may need multiple)
Now, I will say that you are going to need injectable antibiotics for a snake, probably baytril (enrofloxacin) or taxicef (ceftazadimine) as orals don't work well for snakes. I don't know about the exotics visit, but the ones in my town are between $60 and $85. Abscesses in mammals rarely require surgery, usually they get lanced then flushed. The resulting "hole" is left open to drain and heal from the inside out. Antibiotics are given to help the current infection and prevent more, they are rarely bandaged (which wouldn't work on a snake anyway)
Hope this gives you some help