Hans, you are wrong. Let's talk seriously about the costs of your dog. Every year, it will need vaccinating and an annual vet check up. It will need worming (and possibly flea treatment) every three months.
These days, any sensible pet owner will have insurance.
It will need an appropriate diet, preferably one not full of crap. It will need a collar, lead, bowls, possibly a coat, a bed, grooming equipment. You will need to bath it regularly and possibly have it professionally groomed/clipped/toenails clipped, depending on breed. If you have a car, you will need some form of safe transport system for it, such as either it's own seat belt, a dog guard for the boot, or a travelling crate/cage, as well as possibly some form of seat cover/blanket to protect from mud/hair.
You will need to take it to classes, either puppy classes if it is young or general obedience classes if it is adult. It may need toys and many owners invest in a crate. When it is an adult, you may well wish to do things like further obedience classes, Cani X, flyball etc. Even going further afield on walks will cost in petrol and time.
When you go on holiday, your dogs will need to go into kennels. This will cost as much as taking another person on the holiday. If you are busy in the day you may need to pay for a dog walker, and there may well be times when you will have to pay for care for your dog when you are away/having a day out etc.
Your home and garden will need to be dog proofed. This means that your fencing needs to be secure. We've just spent the last five days with our three dogs taking it in turns to vomit copiously all over the house (food poisoning - all are now recovering) - the washing machine has been going non stop, the curtains are at the dry cleaners and several large duvets are at the laundrette, and we've had to throw out two rugs. We've had to pay for vets visits - although we are insured cost will be beneath excess, so we are out of pocket for that. This is by no means unusual (not the food poisoning) but the fact that we visit our vet regularly for small things and that we need to do a great deal of extra housekeeping because of the dogs.
ALL OF THIS COSTS. A LOT. We have chosen it, and are happy to pay it. But the point is even for one or two dogs, this is expenditure you will need to find.
I would strongly recommend that you do a spreadsheet of your monthly budget, income and outgoings and take a long cold hard look at whether you can afford a dog.
You do not have a right to a dog. Bluntly, if you cannot afford it, all the love in the world will not help you, and more importantly will not help the dog.
If you really want to help a second dog, you might want to think about fostering, but to be honest I am reluctant to recommned that since you seem to be hostile to charities visiting you. All the reputable charities I know (and I do these visits myself) only tend to do one homecheck visit before an adoption - our charity usually does a courtesy follow up visit after the dog has been adopted to see how it is settling.
If you paid £100 for a pup then that was too little. Any of the reputable dog breeders on MN (and there are some) will tell you that this will not cover the cost of the pup if it has had the apppropriate care, including medical attention, vax and worming (essential for pups, and for pregnant mum).
As a charity trustee, I can tell you that the suggested adoption fee of around £100 - £125 will not come even close to covering the costs of the dog. These will include neutering, chipping, vax, worming, flea treatment, full vet check, often dental work (I volunteer for greyhound charity), any other veterinary work, behavioural assessment, etc etc as well as food and kennelling costs. As well, many charities will also ensure that if the dog ever has to be rehomed (no matter how old) it will be taken back. We currently have an 11 year old greyhound who was handed back last year to the charity - would your breeder friend be willing to do that in ten years time?
Hans, please think hard about this.