I can understand the desire to charge for the upgrade to cover the costs of you starting a legitimate business, but this seems to have gotten out of hand.  I have a personal e-mail from you encouraging me to buy the Simple Trade Bot before January so I could catch the lower price before the free upgrade.  I did just that, but now with this "upgrade fee" it will end up costing exactly the same as if I had just waited.  All in all, I'm not really losing out, but you need to look at it from a start-up business perspective.  Your initial customers are the ones you need to be catering to right now.  The ones who worked with the old version are the ones who will be going around talking about how great the update is, and how great the support from your company was.

I'm not trying to bash you... I'm just trying to give some advice.  Look at it this way, if you were promised by a store that you could buy the 2013 model of a computer and a guaranteed free upgrade to the 2014 model, wouldn't you be pissed if they told you that you were now required to pay 10% of what you already paid?  The numbers may seem small, but it's the idea behind it all.

Maybe you should consider dropping everything down a tier.  Everyone who bought the bot prior to the upgrade is simply required to give a "donation" of any amount over ~$1.  These people could also opt into an upgrade for the advanced version for whatever price you set.  Anyone who hasn't bought the bot yet will be required to pay full price for whatever tier they're opting into.

Edit: I just took a look at the new website and noticed that these are 1-year licenses that you're selling.  Is that also the case for the prior customers?  Does that mean that we're paying .05BTC for use of the upgrade for one year, or are previous customers locked in for life?