Laravel error inserting data into table from another table

I'm trying to insert into product table a form data and one field which i pulled from another table called Purchase by using the code below

 Product::create([
            'purchase_id'=>$request->product,
            'price'=>$price,
            'discount'=>$request->discount,
            'description'=>$request->description,
            'purchase_purchaseprice' => Purchase::where('id',$request->product)->get('price'),
        ]);

But i get this error message, and i think the issue is this [{"price":"25.00"}]but i failed to format the query to insert only 25.00 amount, Please help ?

Illuminate\Database\QueryException SQLSTATE[22007]: Invalid datetime format: 1366 Incorrect decimal value: '[{"price":"25.00"}]' for column laravel.products.purchase_purchaseprice at row 1 (SQL: insert into products (purchase_id, price, discount, description, purchase_purchaseprice, updated_at, created_at) values (262, 4000, 0, ?, [{"price":"25.00"}], 2021-11-19 18:25:59, 2021-11-19 18:25:59))

source https://stackoverflow.com/questions/70039524/laravel-error-inserting-data-into-table-from-another-table