|Swift has been purchasing Beatles memorabilia|
A source told the Daily Star newspaper: "Harry spent £900 on Taylor for her recent birthday and now she wants to repay the favour - and then some.
"She's been phoning Beatles stores in Liverpool hoping to find pieces of rare autographed memorabilia she knows Harry will love.
"A staff member at one store let slip she wanted to spend somewhere between £40,000 and £50,000."
Taylor turned 23 earlier this month and was showered with gifts by the British singer, including a Jimmy Choo bag,
antique earrings, perfume, and a black and white photo of the 'I Knew You Were Trrouble' hitmaker in a vintage frame.
Harry, 18, has previously praised The Beatles as "icons" and admitted he finds comparisons between his chart-topping group and the 'She Loves You' hitmakers "ridiculous".
He has said: "We watched that film of The Beatles when they touched down in America and saw a likeness with our personalities. They loved having a laugh like us.
"[But] the comparisons seem ridiculous to us, because they were such icons."