We adopted a 3 month old puppy from a Spanish rescue. Cost was still around £600 and on top of that we had to travel for around 2 hours for collection as the transport (Spain to UK) only brought them so far. Having looked extensively before we took the leap, Romanian rescues are also similarly priced.
The plus side is that they tend to have younger dogs available as the stray/ pregnant abandoned dog problem is so rife over there. They also often have older dogs available that have been with them for a long time so they know their personalities well and can give advice on whether its a good match.
Downsides is that even the younger dogs will have been through some trauma; either born on the streets and been hungry or possibly abandoned/hurt by people. You have to go in with your eyes open that it's going to take these dogs longer than normal to acclimatise.
We've had our dog for 3 years now and wouldn't be without her. We had a dog behaviourist at the beginning to help us settle her in but she'll never be the 'Andrex puppy rolling on the floor with the neighbours' type of animal. She adores her family but not remotely interested in other people and can be very stand-offish. Suits our lifestyle fine but its not for everyone.
Big plus side for us is that she is tough as old boots. My sister has two pedigree dogs that get the runs as soon as they look at anything that's not chicken and rice where as our rescue eats anything she's given, has a lovely shiny coat, would run all day and is an easy delight. We pay £15 a month for lifetime cover pet insurance and outwith the initial spaying/flea treatments etc, she's only been to the vets once and insurance covered it all except excess. So, not every dog needs £1500 per annum on vet fees. I'm a very experienced dog owner and I've never had a simpler, easier to train, easier to look after doggo than my lovely wee street mutt 😍