Should I buy the new or upgrade the old?

Hi, in a few words:

Weighting between a DIY upgrade fix vs. buying a new Macbook Pro. Which is the best cost-effective option?

I have a A1502 Macbook Pro:

Processor Name: Intel Core i5


Processor Speed: 2.6 GHz


Memory: 8 GB


Chipset Model: Intel Iris


VRAM (Dynamic, Max): 1536 MB

I need a graphic card like:

1. AMD FirePro D300

2. AMD FirePro D500

3. AMD FirePro D700

4. AMD Radeon R9 M290X

5. AMD Radeon R9 M380

6. AMD Radeon R9 M390

7. AMD Radeon R9 M395X

8. Intel® HD Graphics 6000

9. Intel® Iris™ Graphics 6100

10. Intel® Iris™ Pro Graphics 6200

11. GeForce GTX 675MX

12. GeForce GTX 680

13. GeForce GTX 680MX

14. GeForce GT 750M

15. GeForce GT 755M

16. GeForce GTX 775M

17. GeForce GTX 780M

18. Quadro K5000

Thanks very much!