Prices are going to be a bit variable – its generally bulky stuff so your market, through ebay, is going to be limited to people who are close enough to collect.
You’d expect the welder to potentially be the most valuable bit. However its 3 Phase which is going to limit you to buyers who have an industrial 3 phase power supply to their premises. There is lots to go wrong with a mig welder, so premium price would depend on whether you can vouch for its condition, and also how available spares are to keep it running. It looks to me like they may no longer be in production – there is an Indian company called Arc Tec, but seeming no longer a UK one. A quick google throws up a few models like yours that have gone through industrial auctions for less than £100, which seems very cheap for what looks like a pretty serious piece of kit, but maybe showing that obsolesence is the issue. If a bidder got giddy they might spend up to £300. An equivalent new machine would probably £700 – £1000, possibly more.
The pipe bender looks like ones Machinemart.co.uk sell.
Bench grinder is unlikely to fetch more than £20, no matter what it cost there are so many cheapo new ones about it caps the value of old ones secondhand
Smaller pillar drill would prob fetch about £100. There is less to go wrong with them, so people will be braver when bidding
the larger one that is in bits is also 3 phase, like the welder, that limits the appeal and although it should sell for more it would prob sell for less
That style of horizontal band saw prob sells for £300 – £800 new. Maybe hope for around £100 second hand, again they can be a bit complex and maintainance thirsty which would make buyers wary of a second hand machine, the recent introduction of cheaper, simpler TCT chop saws limits the appeal of bandsaws a bit.
Ebay is one option for selling, but to maximise their value you need to be able to give very good descriptions, another option would be a specialist auctioneer, round my way that would be Sweeney Kincaid. Either route its hit and miss what they’ll actually fetch.