Hi Manoj,
I think the P3 with a Elys is a good choice for an entry to the vinyl world. There are quite a number of budget phono amps available also. But my recommendation is don't buy too cheap. Good and reasonably priced amps which I have heard are: Lehmann Black Cube 2 @ appox. 450 Euro
Lehmannaudio :: HighEnd vom Toningenieur :: Black Cube and Trigon Vanguard 2 @ approx. 380 Euro
Trigon Audio - Elektronik GmbH Kassel . Vanguard2 has the advantage that you can upgrade this amp with an external battery power supply Volcano2 for another 380 Euro.
Trigon may not be known to many here on the forum. Before starting the company the owners have done a lot of OEM developments for reputed HiFi manufacturers. Their most outstanding development at that time was perhaps the legendary Ortofon step-up transformer (now out of production) for the SPU pick-ups.
Regarding an upgrade for the cartridge my recommendation is the one and only Denon DL103. Works very well with the RB300 arm. Otherwise there are again so many alternatives. If you don't want to go for DL103 just look in the product cataloges of Ortofon and Audio Technica. I'm sure you'll find something that suits you.
Regards,
Jochen Semler
The Listening Room
Bangalore
P.S. Just call me by my given name Jochen please.