The eBay model is about 4 times the cost as what I paid for my E44. But it looks like there's a very good drive unit inside, but it's termed " bastelmodell" (=needs work) in the description and there are loose parts included. I would check first if the drive really runs OK.
I'm sticking with the E44 I have . The Pola maxi T3 is still available from Schnellenkamp for a reasonable price. I haven't bought it because in the past I've bought a Rai-Mo Crocodile kit and then shortly thereafter came across an already built motorised Crocodile for about half the price of the complete kit. The same happened with a Rivarossi 0-8-0 American Steam locomotive...