My dog has cut his paw

My dog yesterday has cut the top of his foot, he seemed fine wasn’t in pain and was running around still on the walk on the way home and was fine last night, I contacted my mum for some cream to help it as she has dogs herself and has a lot of dog Medication just to help him with it a little bit. This morning I’ve woke up and he’s limping and won’t put his foot down at all but he’s still his normal self doesn’t seem in that much pain at all he just seems hesitant to put pressure on it I am wondering if I should take him to the vets? My mum has said to give it a day or two and to use this wound spray she got from the vets, I’ve also cleaned the wound with luke warm water and salt this evening just to keep it clean, admittedly I want to hope it’s not a trip to the vets as last time I went with my other dog who was in the exact same situation with his foot they gave him an antibiotic a consultation and sent me on my way with him and it cost me just over £200, with the cost of living right now understandably moneys abit tight but will have to just suck it up if he does need to go as that’s what’s in my dogs best interest but just wanting to get some advice before I had to resort to the vets, I will attach a photo. 

I'm sorry;  I hear your frustration, especially in the current financial climate.  I also hear that your dog doesn't look as though he's in pain - dogs often don't and indeed, this conversation comes up very commonly in consultations - but let's think about limping for a minute.  The very act of limping is where it hurts to put the foot / leg down normally, so you (or they) walk in a funny way.  Most people have experienced this effect eg having a sharp stone in their shoe.  Indeed, by definition, most dogs that limp are in pain.  (The exceptions are some very rare neurological cases but as far as I can tell, that's not what's happening here).  The other thing is that I think I can see a lump / swelling on top of the foot in this picture.  This is, at best, inflammation eg from biting (another sign of pain), or possibly an abscess or foreign body and at worst something much less desirable eg a sinister lump.  Antibiotics might be helpful if it was an abscess but I am not yet convinced thats the story - even if it was, there is a very real risk of this getting worse.  Please do take this foot and it's owner to see a vet, sooner rather than later.  From what you have described, I do think that it might prove very worth while.