Sure it's expensive but a normal CTC or OAA grad is going to be in a similar position without the conditional job offer.
I think that's scraping the barrel of potential reasons to apply....
Even if you ignore the "training salary" (which will not be pretty) and assume payment holidays/savings can tide you over, 20000 euro is what you have to live on. Take off at least 12000 for loan repayments, that leaves 660 euro/month + sector pay, before tax. Put into context, you can earn that by working just over half time in any minimum wage job in the UK. Granted cost of living in Eastern Europe will be lower, with sector pay you might even be able to afford to live, but life is still going to be a struggle for years. Then there's all the "what ifs". What if interest rates go up? (they will), what if the salary is cut at some point in the future? (not unheard of in aviation), what if the cost of living increases or your circumstances change? Your salary that is already marginal at best becomes completely unsustainable.
If you have the cash to avoid a loan it might be worth a punt, the salary looks better without having to pay 1000/month for X years. But even then, if you have the money why not go for the EZY MPL or CTC Wings routes...