SimpleThe mills not running -so add start up costs including...

Simple
The mills not running -so add start up costs including hiring costs and mobilisation to site of personnel and contracting plant ++++$
Tailings dam is now full - Oh dear me more money and work before restart.++++$
The spare WGX ore sitting in stockpiles that would have been profitably trucked to a running mill when they made their original offer have now been slowly monetised by WGX- so no immediate positive cash-flow on a quicker mill restart and there will NOW be a need to build up a mined ore stockpile before a mill restart++++$
The current market price is ridiculous if any takeover premium applied.++++$
The underground development costs to get SPR to profitable ore or upgrade of mill to use surface stuff add up.++++$

Easier and better immediate value to buy something already operating for immediate cash flow or far far cheaper to buy dormant assets with tenements and do your own drilling without starting with a FULL RETAIL premium of $630 million +++++++++ plus cost and adding all the extra's and risks involved in it before you see a return on your cash or any ore mined.

There is at least one other non operating mill of similar size and rather sparsely explored tenements around a similar size to SPR with one in admin/recent admin at the moment.
Around the same distance from any existing CUE ore and remaining stockpiles.
No doubt that will be a lot cheaper and it has pre-approval to handle Cue sands resource at max of 15% of mill feed.
One could assume those original surplus WGX Cue stockpiles were originally planned to go through this mill for a bit of stray cash to WGX before it went under.

DYOR + DYODD I know what i'd be chasing with my money.
SPR is dead as far as WGX is concerned.
It had a bargain price ONCE and an immediate value accretion to WGX ONCE at that price, with enough WGX ore to keep a RUNNING MILL running profitable for 18 months with immediate cash flow ,with 6 months left on the tailings dam before a lift needed,but no longer has any of this immediate value,NOW It's just expenses to be had on top of expenses on top of acquisition costs to get it up and running again.