not sure how prices compare for your specific drug but i use vetmedsplus, they were 25 quid cheaper for the meds i needed, very quick and only £1 postage!
Defineately worth doing a google search - I wanted Prednisolone & bute but found significant savings by going to separate companies - postage v cheap or free so it doesn't matter if you split them, just get separate prescriptions from vet. Mine just charged me for 1 even though they were on 2 pages (what a star !)