Option Explicit

'http://steamcommunity.com/market/priceoverview/?currency=5&country=us&appid=11111&market_hash_name=22222&format=json
'вместо 11111 должно быть значение из 1 колонки, а вместо 22222 - из второй.
'Пример ответа: {"success":true,"lowest_price":"71,08 p\u0443\u0431.","volume":"1,126","median_price":"70,56 p\u0443\u0431."}
Sub qwerty()
Dim i, r, a, b, s, u, lr
With Лист3
lr = .Cells(.Rows.Count, 1).End(xlUp).Row
.Cells(2, 3).Resize(lr - 1, 3).ClearContents
For r = 2 To lr
    a = .Cells(r, 1)
    b = .Cells(r, 2)
    s = "http://steamcommunity.com/market/priceoverview/?currency=5&country=us&appid="
    s = s & a & "&market_hash_name="
    s = s & b & "&format=json"
    i = GetHTTPResponse(s)
    Debug.Print i
    u = Split(i, ":")
    .Cells(r, 3) = Replace(Trim(Replace(Split(u(2), "\")(0), "p", "")), Chr(34), "")
    .Cells(r, 4) = Replace(Trim(Replace(Split(u(4), "\")(0), "p", "")), Chr(34), "")
    .Cells(r, 5) = Now
Next r
End With
End Sub

   Private Function GetHTTPResponse(ByVal sURL As String) As String
     Dim oXMLHTTP
     On Error Resume Next
     Set oXMLHTTP = CreateObject("MSXML2.XMLHTTP")
     With oXMLHTTP
        .Open "GET", sURL, False
        .SetRequestHeader "Cache-Control", "max-age=0"
        .SetRequestHeader "User-Agent", "Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/48.0.2564.41 Safari/537.36 OPR/35.0.2066.10 (Edition beta)"
        .SetRequestHeader "Accept-Encoding", "deflate"
        .SetRequestHeader "Accept-Language", "ru-RU,ru;q=0.8,en-US;q=0.6,en;q=0.4"
        .send
         GetHTTPResponse = .responseText
     End With
     Set oXMLHTTP = Nothing
End Function

Sub qwerty()
    Dim i, r, a, b, s$, u, lr
    Dim objReg, pr, j
    With Лист3
        lr = .Cells(.Rows.Count, 1).End(xlUp).Row
        .Cells(2, 3).Resize(lr - 1, 3).ClearContents
        For r = 2 To lr
            a = .Cells(r, 1)
            b = .Cells(r, 2)
            s = "http://steamcommunity.com/market/priceoverview/?currency=5&country=us&appid="
            s = s & a & "&market_hash_name="
            s = s & b & "&format=json"
            i = GetHTTPResponse(s)
            j = 0
            For Each pr In Array("lowest_price", "median_price")
                With CreateObject("VBScript.Regexp")
                    .Pattern = pr & """:""+(\d+,\d+)"
                    Set objReg = .Execute(i)
                    If objReg.Count > 0 Then
                        .Pattern = "(\d+,\d+)"
                        Set objReg = .Execute(objReg(0))
                        If objReg.Count > 0 Then Лист3.Cells(r, 3 + j).Value = objReg(0)
                    End If
                    j = j + 1
                End With
            Next pr
            .Cells(r, 5) = Now
        Next r
    End With
End Sub

Sub qwerty()
    Dim i, r, a, b, s, lr, json
    With Лист3
        lr = .Cells(.Rows.Count, 1).End(xlUp).Row
        .Cells(2, 3).Resize(lr - 1, 3).ClearContents
        For r = 2 To lr
            a = .Cells(r, 1)
            b = .Cells(r, 2)
            s = "http://steamcommunity.com/market/priceoverview/?currency=5&country=us&appid="
            s = s & a & "&market_hash_name="
            s = s & b & "&format=json"
            i = GetHTTPResponse(s)
            Debug.Print i
            With CreateObject("scriptcontrol")
                .Language = "jscript"
                Set json = .eval("(" & i & ")")
            End With
            On Error Resume Next
            .Cells(r, 3) = json.lowest_price
            .Cells(r, 4) = json.median_price
            On Error GoTo 0
            .Cells(r, 5) = Now
        Next r
    End With
End Sub

Private Function GetHTTPResponse(ByVal sURL As String) As String
    Dim oXMLHTTP
    On Error Resume Next
    Set oXMLHTTP = CreateObject("MSXML2.XMLHTTP")
    With oXMLHTTP
        .Open "GET", sURL, False
        .SetRequestHeader "Cache-Control", "max-age=0"
        .SetRequestHeader "User-Agent", "Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/48.0.2564.41 Safari/537.36 OPR/35.0.2066.10 (Edition beta)"
        .SetRequestHeader "Accept-Encoding", "deflate"
        .SetRequestHeader "Accept-Language", "ru-RU,ru;q=0.8,en-US;q=0.6,en;q=0.4"
        .send
        GetHTTPResponse = .responseText
    End With
    Set oXMLHTTP = Nothing
End Function