Who is the cheapest link?

One of my favourite ways to select defenders is to select a player from a team who is valued at a lower value than his teammates (like Armand Traore last year who at 4.5m was considerably cheaper than his Portsmouth teammates). A lot of fantasy players tend to select a particular player based on reputation even though you are really picking a defensive team, save for a extra goals and bonus points that accompany some players. Putting these aside for now, lets look around the league for the potential cheap links this year:
NB. Goalkeepers do not count here as they are all generally cheaper than the defensive counterparts:

Man United - Rafael (5.5)/O'Shea (5.5)/Brown (6m)/Neville (5.5m)
If any of these players can lock down the position then they instantly become almost a must own player as they will be playing alongside the best defence in the league, who are valued at 8m, 7m and 6.5m but will only cost you the same as a Villa or West Ham defender. If Rafael can become an every week player then his attacking prowess make him even more valuable, and he would easily have 120 point potential. The question of course remains who will play and so far in the post season we are none the wiser:

vs Malaysia XI - Neville RB (O'Shea sub), Brown CB
vs FC Seoul - O'Shea RB, Brown CB
vs Greentown - Fabio RB, Brown CB (sub)
vs Boca Juniors - O'Shea RB, Brown CB
vs Bayern Munich - United played 3-5-2

As you can see this provides absolutely no help whatsoever, so my only advice would be to ignore this situation for now and see what develops. The fact that Brown played in every game but one might suggest he is the favourite but better value can be found elsewhere until this situation becomes clearer.

Liverpool - Martin Skrtel (6m) and Insua (6m)
It is unclear if Skrtel will be ready for the start of the season, but if he is he should join Insua as bargain players in one of the top defenses around, and will only cost 6m (1m less than fellow center back Carragher). I like both these guys to open the season with and would even consider starting both considering Liverpool's good looking schedule.

Aston Villa - Nicky Shorey/Luke Young (5m)
Villa's defense is paper thin right now and if reinforcements aren't made they may concede too many to even be considered a viable fantasy option. Nevertheless, assuming they are a top 8 defense again next year, Young and/or Shorey look like good value ahead of teammates Davies and Cuellar. Young would be the top choice based on the fact he played a lot last year and seems to be ahead of Shorey in the pecking order.

Blackburn - Ryan Nelsen (4.5m)/Givet (4.5)
This one is a bit of a head scratcher as one of the key principles when selecting a defender is whether they will play and who is less likely to be benched than the club captain? Reports from Ewood suggest that Givet fill play at left back allowing Samba (5m) to partner Nelsen in the middle. I wouldn't bet my house on Givet playing every week as they may opt for Warnock at left back when they wish to be more adventurous, but Nelsen looks like a good bet to play 32+ games, and for an improving defensive side like Blackburn, that looks like money well spent.