Concatenate and add formula

Hello Everyone,

I have some cells that contain data and I have concatenated them. I now need to add a formula to the end but have no idea how to do it!
So here is my string and it works fine:

=C8&" - "&G8&""

I now want to a formula that will check cell I and depending on what is entered (1 of 3 options) (A) , (B) or (C) will be added in brackets to the end of the string.

Example:

Cell C contains: 1 Test Street
Cell G contains: PG / FP / EPC
Cell I contains: £500,000 - £900,000
Cell AQ has the following formula:

=C8&" - "&G8&""

And this produces in cell AQ: 1 Test Avenue - PG / FP / EPC

But I need it to produce: 1 Test Avenue - PG / FP / EPC (B) So it will check cell I and if it contains <£500 it will add (A), if cell I contains £500,000 - £900,000 it will return (B) and if it contains >£900,000 it will return (C) to the end.
Meaning if it was working as I would like the result of cell AQ (using the example above) would = 1 Test Avenue - PG / FP / EPC (B)

I have no idea how to add a formula to the end! I have attached an example*

Thank you in advance for your help