Nobody else can really answer the question for you. I've fixed worse, but that's not the question! There's no shortage of rotten Minors at the moment so not like it's the only one left.
If the car has some redeeming features then it adds to its value (decent paint, good doors, wings, nice interior, etc..). If you can DIY all the repairs then the price to fix it becomes worth considering. If you need to pay for it to be restored there need to be some good reasons, for which most people who pay out can find their own justification.
If you can get hold of a car roller, and have room for that, it makes life much more pleasant - I never liked welding whilst laying under a car so when I eventually got mine I wished I'd had it a decade earlier.
Gas bottle rental + welding and grinding consumables + the price of the panels means that you'll not make any money on the project. Either you do it so you can have a car that you rebuilt, or just because you like pet rescue projects, or something else about the car gives you a reason (previous family owner etc..)
As well as sills, floor edges, A-post, front inner wings there maybe repair/replacment needed for centre cross member, rear chassis extensions, rear arch seams, rear spring shackles, boot floor and floor under rear seat.
For what it will cost to repair you could buy a much better project car. If you want to do the project and want to learn the skills (often by learning the hard way!) then by all means!
If there's a big risk that after you buy a lot of the parts it never gets finished, then don't.
There are plenty of rotten Minor for sale and also many unfinished projects where people struggle to get back half what they have spent on the pile of parts included with the car.
The other option is to offload and go for one you can drive from day one. I prefer using them to welding them! (however I'm losing count of how many I saved from scrap along the way

)
Ray. MMOC#47368. Forum moderator.
Jan 06: The Minor SII Africa adventure:
http://www.minor-detour.com
Oct 06: back from Dresden with my Trabant 601 Kombi
Jan 07: back from a month thru North Africa (via Timbuktu) in a S3 Landy
June 07 - back from Zwickau Trabi Treffen
Aug 07 & Aug 08 - back from the Lands End to Orkney in 71 pickup
Sept 2010 - finally gave up breaking down in a SII Landy...
where to break down next?
2013... managed to seize my 1275 just by driving it round the block
