Ryval (new to me) sell the 10 litre (BOC "X" size) pure argon for £40, £50 deposit, £20 shipping (next day) and £12 vat. The 5% CO2 mix for MIG/MAG is £5 cheaper.
Gas-uk.co.uk charge £35 for the same 10 litre size pure argon, plus £50 deposit, £10 delivery and £9 vat. However, they do a nice big 30 litre bottle for £60, £120 deposit, £26 delivery and £17 vat. Much better deal. Cylinder collection is £12 unless you live near St Helens.
As pointed out, Gas-uk gobble your deposit which skews the numbers:
(a) for “SuperMaxx” and “Balloon Gas” Cylinders only: (i) if you return the Cylinder to us within [six] months, we will refund [100%] of the Deposit; and (ii) if you return the Cylinder within [12] months, we will refund [50%] of the Deposit; and, after [12] months, you must return the Cylinder to us in any event and we will not refund the Deposit.
(b) for all other Cylinders: (i) if you return the Cylinder to us within [12] months, we will refund [100%] of the Deposit; (ii) if within [12 to 18] months, [80%] of the Deposit; (iii) if within [18 to 24] months, [50%] of the Deposit; (iv) if within [24 to 36] months, [30%] of the Deposit; and if you return the Cylinder after [36] months, we will not refund the Deposit.
Murray