I think you may have misunderstood the general direction of my posts.
That SME on ebay is a vintage piece. A new SME close to that design is $1000 at needledoctor website. It is a in a different and higher league to Rega arm INMO.
Origin live arm, armboard, good cartridge and outboard phono amp will likely exceed £500(sorry about talking in pounds and dollars)
You are mentioning that certain products are cheaper, if budget is limited then I would just buy one good cartridge.
Even if budget is not limited I would still recommnend just starting with cartridge.
Your other upgrades can then be trialed and tested from that starting point, your ears will tell what you do like and don't like. I still tend to think that just the cartridge may well blow you away. There must be Hi Fi shops that could supply and fit V15 or demonstrate the difference?