What is the Total Cost of Conversion (Excluding the Mill)

[JAZZCNC]

3 phase though. Can't use it without ripping elecs out first and replacing spindle motor.

Not the case because they will happily run from a 3 phase rotary converter. Yes, this up's the cost but this is offset because of not messing around with converting, etc plus you get a real CNC machine, not a Dinky toy.

Not a fan of that style Bport.
Seemed risky to me in case I didn't have the skills to build the mechanics.
Now, if I could've got a blown out Haas mini mill type thing that may have been a different story!.

The mechanics are not much different from any other CNC machine, the principles are exactly the same the differences being they are stronger and better built with accurate datum edges, etc.

Given a choice between an old Bridgeport and a Haas Minimill I'd take the Bridgeport every time. The Haas is just a beefed-up Benchtop Minimill that sits on a steel frame.
The bridge port is one big lump of solid cast iron that will last forever and absorb vibrations like a sponge, it will give finishes and allow material removal rates the Haas Minimill could only dream about.

However, that was just one example and probably not the one I would go for either because there are better newer options if you watch for them, but the point is I wouldn't sink £3.5k which will quickly turn into £5k in all reality into a Chinese machine made from cast iron that is more brittle than a crunchy bar and about as stable as a quivers jelly when you can buy rock-solid old iron for not much more.

In all reality for someone wanting a small desktop machine then Denfords, Boxfords, Emco's, etc which are built from quality cast iron and with decent base components is probably the better way to go.
I'd just avoid converting a Chinese manual machine because it will always be a compromise at best and at worst it's a pig's ear that can't be turned into a silk purse no matter how much money you throw at it.!