The way I read the SAFC takeover was that Stew Don will pay £40m out of his own pocket for the club. Given the huge loss-making situation of the club, likelihood is that he will have to invest significant funds into the club in order for it to meet its day-to-day liabilities. Therefore, SD negotiated to pay the purchase price to Ellis Short in installments to aid his cash-flow - with parachute payments being used as security. Most importantly, cost of takeover to the club is nil i.e. debt was not ported.
Tiger acquired OUFC whose only assets are future transfer incomes for players previously sold under DE. Rather than pay out of his own pocket for the club, he agreed with DE that these future transfer incomes would be paid to the former owner to the tune of £4m. Tiger has/will have to dip into his own pocket for the club to meet its day-to-day liabilities as well. BUT, cost of takeover to the club (rather than the individual) is £4m.
There is, naturally, a possibility I may have mis-understood.
well it can be spun both ways
Stew has to find an extra £25M in the next two years to repay Short on top of the £15M he has already paid, and funding the club and presumably pay the transfer fee creditors. If he doesn't and uses the parachute payments, then it is a cost to the club, because it is taking away income.
Tiger had to find £4M to repay Eales on top of what he has already paid by 2019, and fund the club. If he doesn't, and uses the transfer fees received, then it is a cost to the club, because it is taking away income.
When Eales sold the club, he knew there was guaranteed remainder of fees coming in on O'Dowda, Roofe, Johnson, and Lundstram. If he didn't factor that it into the sale price, he may as well have just given Tiger the money. Secondly there are potential add-ons from those players, such as sell-ons or appearances. Then there are the players that hadn't been sold at the time, such as Ledson, Rothwell, Eastwood, Nelson, all of whom could be assumed to be worth a decent transfer fee - again, not including values for those in the sale price would effectively give them away free to Tiger.
When Short sold SAFC, he knew there was around £45 - £50M of parachute payments guaranteed to come in, so if he didn't factor that into the sale price, he may as well have just given that straight to Stew.