I’ve been talking with smason and he has provided this offer to me.
For £300 or ~$470, I will get the following Jumbos:
JR Rally Jumbo set (3 cards)
Fukuoka Opening (Oshawott)
Tokyo Tower
2010 Happy Birthday
Osaka Opening (Tepig)
Clash at the Summit Celebi & Zorua
Clash at the Summit Zoroark
2012 Battle Carnival Rayquaza
and then I might get the following as well (still have to confirm):
2011 Mincinno
2011 Reshiram
Good deal?
@daelum – If you receive twelve cards, the price is approximately $40 each. It’s a great price for the [2011 JR Rally Jumbo Set], but not for the other cards.
Tokyo Tower, Celebi & Zorua, Zoroark – and even 2010 Birthday Pikachu can easily be obtained for $15 - $20 (each). Pokémon Centre and Carnival Jumbo Cards tend to average $30 - $35.
It is ultimately up to you, however. The [2011 JR Rally Jumbo Set] is incredibly difficult to obtain.
Well smason had originally offered that if I buy the JR Rally Jumbo Set, he’d throw in the rest of the Jumbos he has for auction. I already have like 4-5 of them (both openings, the 2010 birthday, tokyo tower, and the zoroark) so I could sell those to make some money back (around like $115), which would bring the end cost down to around $355.
I guess it would just be better to ask what a good price for the JR Rally Jumbo Set would be 
Daelum, sent you a PM about the JR Rally Jumbo set (3 cards)