WHMCS - Multi currency for diferent product

I've come to a point where I have multiple servers from different countries, and multiple reseller plans from different countries also. Some of them charge me in GBP, others in EUR and others in USD, my issue here is that for example, for a dedicated server I offer to some of my clients I have to pay say EUR$100, and I charge say MXN$1700.00 (not considering my gain), every day I have to check the conversion values cause some days I have to charge MXN$1780, others MXN$1850, MXN$1920, MXN$1635, prices vary a lot so I can't put up a price and hope to heavens that it won't change that much. What I've done is to set up as main currency MXN, so every other currency gets converted to their appropriate value, that is ok for things I know how much are gonna cost to me in MXN, but what happens when I need to base a product, say Dedicated Server that cost me EUR$100.00 and charge it in MXN? I've tried setting the Product at EUR$100 and everything else on 0 but when I apply the conversion pricing, the product goes to EUR$0.00 cause I have the base currency at MXN$0.00. Is there a way to do this? other than me having to check the daily currency exchange and update the prices on all my dedicated servers/products bought in other currencies? Maybe I'm missing something, because to me this is something that should be out of the box, like, "what is the main currency of the product" and select it between the currencies you have available, and of course this is a different topic than choosing your main currency.