CIES Football Observatory are probably the most accurate guide to true transfer values out there, which has been proven over time.
They take in all factors, including the rather important length of contract remaining, which has a significant affect on transfer values.
CIES value Spurs centre-back Cristian Romero at €68.3 million (£58.09 million), compared to Transfermarkt, who value our Argentinian centre-back at just £36m (€42.33m).
I don't even think opposition fans would even argue the CIES figure is the more accurate of the two, Jamie Carragher certainly would, he loves Romero, "has that touch of quality about him".
Spurs have a €50m (£42.53m) purchase option that doesn't have to be activated for a further year.
Initially, as you know, he is on loan until 2023 for which there will be a loan fee, probably broken down by season. If so, then the second year's loan fee can be avoided by buying him this summer.
When he does sign, his contract will be extended I'd expect and thus his CIES valuation will increase. Currently he is valued s the 8th most financially valuable centre-back (asset) in European football.
Transfermarkt valuations are often quoted, I quote them myself, but we must always remember they can be wildly inaccurate, as in this case.
The table below will show you how they value some of our other centre-back targets.
Spurs-linked centre-back valuations
Joško Gvardiol - RB Leipzig - €99.8m (£84.88m)
Matthijs de Ligt - Juventus - €63.2m (£53.75m)
Alessandro Bastoni - Inter Milan - €60.8m (£51.71m)
Pau Torres - Villarreal - €59.8m (£50.86m)
Marc Guéhi - Crystal Palace - €50.5m (£42.95m)
You can see why Tottenham are and were happy to pay €60m for Bastoni, it's an accurate valuation and the valuation for Torres seems accurate too.
Cameron Carter-Vickers will be a Celtic player next season after we reached agreement for his permanent transfer after a season on loan there.
His form has seen him picked for the USA again.
The announcement on the opening day of the summer transfer window demonstrates our journalists hadn't a clue what was going on and we are fed the usual PR nonsense, from agents and players or clubs.
Djed Spence is another example, Bastoni was another, no sooner had he told Inter he wanted to leave, as these journalists reported, they were reporting he doesn't want to leave.
We are talking to Gleison Bremer but he would prefer to stay in Italy. He is also talking to AC Milan after Inter failed to agree a fee with Torino to allow Bastoni to leave.
Midfielders
Moving onto defensive midfielders, Spurs only paid £14.94m (€17.57m) for Pierre-Emile Höjbjerg, who the CIES Football Observatory value currently at €53m (£45.08m).
This clearly demonstrates the value of buying a player with just a year left on their contract and how their valuation then doesn't reflect their true market value, the value when on a longer contract.
It also demonstrates why you shouldn't let a player run down his contract and should only give a wage increase if it is tied to a contract extension.
Both Spurs and Newcastle United have been tracking Lyon's 24-year-old (25 in August) Brazil international attacking-midfielder Lucas Paquetá, but Christian Eriksen is expected to be filling the role next season.
LaLiga side Elche are the second Spanish side to have made an inquiry for Tanguy Ndombele to take him on loan next season.
COYS