They could easily get money with the equity in the club as guarantee . They won't and I'm not saying they should but plenty of private equity would be willing.
Rumours that enic would sell a % of the club to a third party - if structured so its new equity created that means £ x million going into Tottenham Hotspur Limited.
Raising a loan of say £300m to invest in players is expensive as its seen as Russian roulette (our success rate 2016 to 2020 is about 1 player in 10, under Fabio its improved a lot but lets say 7 players in 10 succeed but even within that will we be able to sell Richarlison for more than the reputed £60m we paid ? ) so rates would be nowhere near the 3% stadium finance is. And the financier is likely to want to call in the guarantee of the equity, which means they are in control of the terms they buy the equity on.
IMO it would be better in most scenario to
- sell a minority of the equity to a 3rd party dealing with all the terms (eg board representation, follow on or not if enic sell on and a whole host of other issues). Or
- maybe do a convertible (again setting out terms to buyer) Or maybe - do a bond with a link to repayment being out of revenues from Spurs.
But going to your other point, I'd always opt to pay in instalments. Why ?
If I have £50m I might be able to use that to buy ONE player outright or pay for FIVE £50m players on 5 year contracts by paying 5 x £10m instalments in year 1 - effect on cash flow is the same in year 1. Of course buying 5 players it means I have £200m creditors at the end of year 1 which is paid off at £50m (5 x £10m instalment) in each of years 2 to 5.
This results in spreading/leveraging your money without paying a financing charge - which is why most transfers are done by paying in instalments rather than up front,