Thanks for your replies, that does help! I did see an exotics vet and I appreciate this would be more expensive, just seemed quite steep for a basic check up!
Keep in mind that the basic consultation fee is not just for the service rendered but that is calculated to cover the basic running costs of the clinic. Clinics with very low consultation fees are usually run by a charity which raises the extra cost via fundraising/donations.
Vet clinics can run from charity clinics with very low consultation fees that aim to allow basic vet access for anybody with a pet to clinics that are run for profit; there is the whole range out there. Ultimately, you want to find a good mix between guinea pig experience and what you have to pay for it. This varies from place to place as access to vet care is not evenly distributed. It also very much depends on your financial abilities and what level of vet care you are aiming at.
But there is no such thing as a cheap pet and you either better start saving up as part of the weekly/monthly maintenance cost or take out insurance. A major operation or a complex health issue can cost you several hundred pounds/dollars in one go. I've had months where I was a £1000 lighter in a matter of a couple of weeks due to two piggies being ill at the same time and needing medical procedures.
You should always have enough in your kitty to pay for late evening/middle of the night life saving or severe suffering ending emergency trip to the out-of-hours vets where the consultation fee is £100 upward even in a place run by a charity, not counting any medication. I am currently £130 (£120 for consultation and £10 for wound care/antiseptic and metacam injection) lighter after having to rush Hyfryd to our single local out-of-hours service in the city very late in the evening because of a heavy bleed on Tuesday night (she is recovering fine); this because of the much higher running cost of the legally required UK wide out-of-hours vet cover - which while costly, has been more than once a real boon for me and saved several lives or saved several piggies hours of dying in total agony.
As a rule in my long term experience, severe illness and emergencies never happen at a good time just by dint of not being welcome anytime and they have a very nasty habit of happening at the most inconvenient time possible. To be provided for that and to at least not having to fret over how to pay for it on top of all the other piggy worries does really help.
PS: Vet cost in the USA and Canada are comparatively much higher than in the UK by the way. A neutering op in New York City can cost you around $1000-1500, just to say... and there is no out of hours cover available in many places.
