20% Guaranteed Return through GOLD ?

Have you ever heard of an investment with Guaranteed Return 20% ?  Well, this particular one is from The Gold Guaranteed . . . what do you think the catch is ?

1. You Buy Bullion Gold from TGG ( The Gold Guaranteed )
2. You keep the gold
3. You sign a 3-months-contract with TGG
4. TGG pays you 1.7% every month
5. At the end of 3 months, you can choose to 
1. renew the contract for another 3 months or
2. sell the gold back to TGG how much you have paid for ( ie. your Capital ) 

• To renew the contract, you have to pay the additional cost if the gold price has gone up
• Like wise if the gold price has gone down, you get paid extra and also gets to renew the contract

For example, at end of August . . .

1. You pay $22,500 for a 100g bullion and signed the 2 pages contract
2. You get paid $382.50 monthly for the next 3 months ( 22,500 x 1.7% )
3. 3 months later, 100g gold price goes up to $23,500.
4. You paid an extra $1,000 and renew the contract
5. You get paid $399.50 monthly for the next 3 months ( 23,500 x 1.7% )
6. another 3 months later, 100g gold price goes down to $21,500.
7. You get paid $2,000 and renew the contract
8. You get paid $365.50 monthly for the next 3 months ( 21,500 x 1.7% )
9. another 3 months later, 100g gold price goes back to $22,500.
10. You paid $1,000 and renew the contract
11. You get paid $382.50 monthly for the next 3 months ( 22,500 x 1.7% )
12. when the contract ends, you sell it to TGG and get back $22,500

Month	paid	get back
1	$22,500	$383
2		$383
3		$383
4	$1,000	$400
5		$400
6		$400
7	-$2,000	$366
8		$366
9		$366
10	$1,000	$383
11		$383
12		$383
		$4,590

Summary

Maximum Capital : $ 23,500

Total Return : $4,590

Rough Return : ~20%

All this happens while you are keeping your own bullion gold with you until you sell it back to TGG.

How does this sound to you ?  What could be the catch if any at all ?

What other strategies you may apply assuming this is a genuine deal ?