Weapon upgrades by Coupons

Well I got 1 suggestion for weapon upgrades. I won Kriss by Black Market more than 1 year ago. Since this time I didn´t won any weapon through black market offer, but I get M4A1 Custom, AWM - Camo, Desert Eagle Camo and Combat Axe, all through owned coupons excange (and I have to admit, it´s not so cheap way to get some weapon).
So I said, If I can´t win any other weapons using Black Market spining wheel, It could be nice if I could upgrade my existing weapons by using coupons exchange.
This is some suggestions for upgrades:

1. D.E. Camo -> upgrade to D.E. Scope (20 Coupons)
2. D.E. Camo -> upgrade to D.E. Gold (30 Coupons)
3. AWM -> upgrade to AWM Camo (35 Coupons)
4. AK-47-> upgrade to AK-47 - Knife (20 Coupons)
5. AUG -> upgrade to AUG Camo (20 Coupons)
6. SSG 552 -> upgrade to SSG 552 Camo (20 Coupons)
7. MP 5 -> upgrade to MP 5 Silenced (30 Coupons)
etc...

My idea is simple. If I can´t win some Black Market weapon (personaly I spend 50000 ZP and didn´t get MINIMI yet), let me upgrade some of my owned weapons using coupon exchange.

Tell me what do you think about it.