sent/won ratio

I assume you mean Real CV ratio?
Go to http://www.sgtools.info/real-cv, input your SG username and write down your real CV numbers for Won and Sent, separately. Then calculate the ratio between those two numbers.
Then try again after adding the value of the game you are thinking of giving, and see if you hit the target ratio. Alternatively, solve the equation for target ratio as the unknown variable to calculate exactly how much you need to spend. Remember to account for bundled games.
If you are talking about RAW value ratio, then you can simply look at your account page on SteamGifts since that's what it'll show.
If you are talking about # of gifts ratio, then you can simply look at your account page and count.

your current numerical ratio is 18:30 in other words 0.6. Knowing that you can easilly calculate how many games you have to deliver to get desired ratio. SGT can also use Value Ratio (same story) or Real CV ratio - in 2nd case check your real CV on SGT: http://www.sgtools.info/sent/Anknownlolz/newestfirst http://www.sgtools.info/won/Anknownlolz/newestfirst and calculate how much real value you gotta give away too meet criteria

Your sent is 53.20 http://www.sgtools.info/sent/Anknownlolz
your won is 90.75 http://www.sgtools.info/won/Anknownlolz
So 2€ won't get you anywhere.